1. Field of the Invention
The present invention relates to an optical component casing, an optical device and a projector.
2. Description of Related Art
Conventionally, a projector has been used for presentations at conferences, academic societies, exhibitions and the like. Such a projector houses a plurality of optical components therein, so that a light beam irradiated by a light source is modulated and then projected in an enlarged manner to form a projected image by using these optical components.
As for these optical components, there has been used an optical modulator that modulates the light beam irradiated by the light source, and an incident-side polarization plate as well as an irradiation-side polarization plate respectively arranged on both sides of the optical modulator.
Here, the incident-side polarization plate and the irradiation-side polarization plate control a polarization direction to which the light beam enters the optical modulator and also a polarization direction to which the light beam is irradiated from the optical modulator, the respective polarization axes being arranged to be orthogonal to each other. With this configuration, high-contrast is provided for the projected image.
Accordingly, a projector provided with an adjusting mechanism for adjusting angle formed by the polarization axes of the incident-side polarization plate and the irradiation-side polarization plate has conventionally been known (for example, see JP2000-259093A).
This adjusting mechanism is provided separately from an optical component casing for housing optical components, and arranged at a predetermined position in the optical component casing. By operating, the adjusting mechanism through a hole formed on an upper side of the optical component casing, the posture of the incident-side polarization plate is adjusted relative to the irradiation-side polarization plate in a plane orthogonal to an illumination optical axis.
Nowadays, a configuration that uses a phase difference plate, a visual-angle correcting plate or the like as an optical component has been utilized for adjusting visual field angle for each of optical modulation elements, and restricting unevenness of a screen due to visual field angle dependency generated at each of the optical modulation elements to form an evenly colored projected image. For instance, the above phase difference plate, visual-angle correcting plate or the like is disposed between the incident-side polarization plate or the irradiation-side polarization plate, and the optical modulator on the illumination optical axis.
When the adjusting mechanism described in Patent Document 1 is applied to these various optical components such as the incident-side polarization plate, the phase difference plate or the visual-angle correcting plate, and the irradiation-side polarization plate, the adjusting mechanism is necessary to be arranged for each of the optical components, thus requiring a wide space in the optical component casing. Accordingly, the optical component casing may grow in size, and disturb downsizing of the projector.
Further, in order to attach each of the adjusting mechanisms to the optical component casing, a plurality of attachments corresponding to the adjusting mechanisms must be formed in the optical component casing, or a plurality of fixing members such as screws are necessary for fixing the adjusting mechanisms to the optical component casing. Therefore, it is difficult to decrease the production cost of the projector due to forming of the plurality of attachments as well as the necessity of the plurality of fixing members.
In this point of view, an object of the present invention is to provide an optical component casing, an optical device and a projector that can decrease the size and the production cost thereof.